In EOT (Emergency Operations Team), SWAT (Special Weapons and Tactics), ERT (Emergency Response Team) and other law enforcement or hazardous operations the goal of a remote communication system (cable and/or wireless) is to reliably control a mobile robot carrying tools, firearms, etc., while providing a safe standoff distance between the operator and the danger area. Generally a communication system has three segments working in parallel: video, audio, and data or control. The communication system is the link between the mobile robot and the operator control station or any supervisor at a remote location.
Current mobile robots use only one form of communication mode at a time, either cable or wireless radio frequency (RF). The cable system may be a multiconductor, coax or fiber optic system. Cable systems provide very reliable communication, but impair the movement of the robot in tight spaces, or when the robot is moving repeatedly forward and backward, and around buildings. Cable systems are limited physically by the length of their cables.
Wireless RF system allows the robot to move freely, but the communication is not always reliable because of electromagnetic interference. This situation is particularly noticeable in video communication. Wireless systems are becoming very expensive if the range required is in excess of 500 m. Moreover, the wireless is notoriously unstable.